Controlled release delivery system for nasal application of neurotransmitters

ABSTRACT

This invention relates to a galenical gel formulation for nasal administration of neurotransmitters/neuromodulators such as dopamine, serotonin or pregnenolone and progesterone. The special lipophilic or partly lipophilic system of the invention leads to high bioavailability of the active ingredient in plasma and brain caused by sustained serum levels and/or direct or partly direct transport from nose to the brain.

INCORPORATION BY REFERENCE

This application is a continuation-in-part application of InternationalPatent Application Serial No. PCT/EP2007/008409 filed 27 Sep. 2007,which published as PCT Publication No. WO/2008/040488 on 10 Apr. 2008,which claims benefit of U.S. Provisional Application No. 60/828,109filed 4 Oct. 2006.

The foregoing application, and all documents cited therein or duringtheir prosecution (“appln cited documents”) and all documents cited orreferenced in the appln cited documents, and all documents cited orreferenced herein (“herein cited documents”), and all documents cited orreferenced in herein cited documents, together with any manufacturer'sinstructions, descriptions, product specifications, and product sheetsfor any products mentioned herein or in any document incorporated byreference herein, are hereby incorporated herein by reference, and maybe employed in the practice of the invention.

FIELD OF THE INVENTION

The invention generally relates to a formulation used for the controlledrelease and delivery of neurotransmitters and neuromodulator agents tothe systemic circulation and/or to brain tissue via administration tothe nasal cavity.

BACKGROUND OF THE INVENTION

A growing body of evidence suggests that brain-acting compounds, such asneurosteroids (e.g., androgens, progestins) or neurotransmitters (e.g.,dopamine, derived from 3,4-dihydroxyphenylalanine (L-DOPA, or levodopa),serotonin, epinephrin, norepinephrine), have a modulatory role in theregulation of disorders influenced by receptors in the brain, such asdepression, Parkinson's disease, Alzheimer's, psychiatric disorders andeven loss of libido and aggression.

Neurosteroids act as modulators, either as stimulators or inhibitors, ofseveral neurotransmitters. Neurotransmitters are chemicals that relay,amplify and modulate electrical signals between a neuron and anothercell. Some neurotransmitters are excitatory, while others are primarilyinhibitory. In many cases, as with dopamine, it is the function of thereceptor which determines whether the transmitter is excitatory orinhibitory.

The brain floats in about 150 ml of cerebrospinal fluid (CSF), whichslowly circulates down through the four ventricles, up through thesubarachnoid space and exits into the cerebral veins through thearachnoid vili. Since the brain has no lymphatic system, the CSF servesas a partial substitute. While the brain and CSF are separated by thesomewhat permeable pia mater, the blood-cerebrospinal fluid barrier andthe blood-brain barrier (BBB) represent substantial protection againstundesirable blood substances.

The BBB creates a protected chemical environment wherein certainmolecules are able to perform functions independent of the functionsthose molecules may perform elsewhere in the body. One example of such amolecule is the neurotransmitter dopamine. When applied as an infusion,dopamine may be used for the treatment of heart attacks or kidneyfailure, but this mode of administration of dopamine is not suitable forthe treatment of neurological disorders, such as Parkinson's disease.

L-DOPA is typically used to increase dopamine levels in the brain forthe treatment of Parkinson's disease and Dopa-Responsive deficienciesbecause it is able to cross the blood-brain barrier, whereas dopamineitself cannot. Once L-DOPA has entered the central nervous system (CNS),it is metabolized to dopamine by aromatic L-amino acid decarboxylase.

Often, during treatment of neurological diseases such as Parkinson'sDisease, L-DOPA is administered to patients together with othercompounds, including carbidopa, benserazide, and Entacapone/tolcapone.Further, other drugs or complimentary therapies may be administered toParkinson's patients in concert with L-DOPA treatment, includingdopamine agonists, MAO-B inhibitors, glial-derived neurotropic factorfor gene therapy, and several neuroprotective agents.

To increase the efficacy of medicinal treatments of CNS disorders,delivery of molecules to the brain via delivery to the nasal cavity hasbeen investigated. The inventors have recently provided evidence inBanks, et al. (J Drug Target. 2009 February; 17(2):91-7), incorporatedherein by reference, that intranasal administration of testosterone isable to target the brain, and in particular, is able to target theolfactory bulb, hypothalamus, striatum, and hippocampus. Drug deliveryto the brain via the nasal cavity potentially offers many advantagesthat include direct access to the brain, rapid adsorption into the nasalmucosa due to the abundant presence of capillary vessels in the nose,rapid onset of action, avoidance of hepatic first-pass metabolism,utility for chronic medication, and ease of administration. However,still little is known on factors controlling the nasal delivery of drugsto the brain. A drug can reach the brain by different ways, includingolfactory neuronal pathway, extraneuronal olfactory epithelial pathway,trigeminal nerve pathway, systemic pathway. It is also possible thatmore of the aforementioned pathways may contribute to the delivery ofthe molecule to the brain. Once a drug is in the brain, it's amount canbe further influenced by BBB efflux transporter systems.

Thus, there has been a long-felt need in the art for investigations intoand the generation of formulations that facilitate molecular uptake intothe tissue of the nasal cavity, thereby increasing the concentration ofthe drug in brain tissue.

However, maintaining clinically effective drug concentrations in vivo,particularly in brain tissue, has been a challenge. The time periodduring which molecules may become absorbed is reduced as a result of therapid mucociliary clearance of a therapeutic agent from the site ofdeposition and the presence of enzymes in the nasal cavity, which thatmay cause degradation of the therapeutic agent.

Many efforts have been made in the art in attempt to overcome theselimitations.

GB 1987000012176 relates to the use of bioadhesive microspheres toincrease the length of time that molecules reside in the nasal cavity.It has also been found that the use of enhancers and stabilizersimproves permeability of the nasal membrane and prevents drugdegradation, respectively. PCT/GB98/01147 (U.S. Pat. No. 6,432,440)pertains to the use of in situ gelling pectin formulations for drugdelivery.

Bayne, U.S. Reissue Pat. No. RE29,892 pertains to a method of increasingthe dopamine concentration in brain tissue through administration of acomposition comprising dopamine and a hydrazine compound. The methodallows for administration of the composition topically, rectally,orally, or parenterally. Preferred compositions include hydrazinecompounds such as L-α-hydrazino-α-lower alkyl-3,4-dihydroxyphenylpropionic acid and L-DOPA and its pharmaceutically accepted salts.

Haffner et al., U.S. Pat. No. 4,826,852, relates to the treatment ofpsychoses such as schizophrenia and discloses methods of administratingergolinyl compounds to increase dopamine concentrations in mammalianbrain tissue.

Additionally, Wenzel et al., U.S. Pat. No. 5,624,960, pertains to thetreatment of Parkinson's disease through the oral administration of acomposition containing levodopa and carbidopa (MK-486). Further, Mandelet al., U.S. Pat. No. 6,319,905, relates to the tightly modulatedproduction of L-DOPA in the mammalian brain by gene therapy. In Mendelet al., modulators such as tetrahydropterin (PH4) are used to controlthe generation of dopamine.

Despite the latter attempts to develop an effective nasal deliverysystem, there remains a need in the art to identify a formulation that,inter alia, limits the rate of mucociliary clearance and degradation ofmolecules in the nasal cavity, thereby increasing the brain'savailability to such molecules, particularly neurotransmitters.Preferably, the formulation should have physical and chemical propertiesthat facilitates brain uptake of molecules/drugs, such as dopamine. Theidentification of a formulation that may increase the bioavailability ofneurotransmitters to brain tissue would provide much-needed treatmentoptions for diseases associated with, for example, dopamine or serotonindeficiency in the brain, including depression, Parkinson's disease,attention deficit hyperactivity disorder (ADHD), addiction to drugs andalcohol, and various psychiatric disorders.

Citation or identification of any document in this application is not anadmission that such document is available as prior art to the presentinvention.

SUMMARY OF THE INVENTION

The presently claimed invention demonstrates that the incorporation ofvarious neurotransmitter agents into a unique lipophilic or partlylipophilic formulation, which when delivered to the nasal cavity,results in clinically effective sustained serum levels in plasma andCSF. These levels in turn increase the bioavailability of drugs to thesystemic circulation and to brain tissue.

The presently claimed invention comprises a formulation for nasalapplication comprising: (a) at least one active ingredient selected fromthe groups consisting of a neurotransmitter and a neuromodulator agent;(b) at least one lipophilic or partly lipophilic carrier: and (c) acompound or a mixture of compounds having surface tension decreasingactivity, an amount effective for generation of contact of theformulation with a hydrophilic mucous membrane and optionally (d) aviscosity-regulating agent. The formulation may also contain minorproportions of one or more compounds including but not limited toabsorption promoters, substances that inhibit enzymatic degradation orefflux, preservatives, flavors and antioxidants.

In one embodiment of the invention, the at least one active ingredientis a neurotransmitter. In a preferred embodiment, the neurotransmittermay be dopamine, serotonin, epinephrine or norepinephrine.

In another embodiment, the at least one active ingredient is aneurotransmitter or neuromodulator agent(s).

In yet another embodiment, the formulation may comprise more than oneneurotransmitter and/or neuromodulator agent. In a preferred embodiment,the formulation may comprise dopamine or L-DOPA and their derivatives.

In one embodiment, the active ingredient(s) may comprise 0.01 to 6% byweight, preferably 0.1 to 4% by weight, more preferably 0.5 to 2% byweight, and most preferably at around 2% by weight of the formulation.

In one embodiment of the invention, the lipophilic carrier may compriseoil, fats and/or other lipids. Lipids may be any lipophilic molecules,including but not limited to fats, oils, waxes, cholesterol, sterols,monoglycerides, diglycerides, phospholipids.

In a preferred embodiment, the oil is a vegetable oil. Most preferably,the oil is caster oil.

In yet another preferred embodiment, the oil may between 30% and 98% byweight, preferably between 60 and 98% by weight, more preferably between75% and 95% by weight, even more preferably between 85% and 95% byweight and most preferably around 90% by weight of the formulation.

In a further embodiment, component (c) may comprise at least onesurfactant selected from the group consisting of lecithin, fatty acidester of polyvalent alcohols, of sorbitanes, of polyoxyethylensorbitans,of polyoxyethylene, of sucrose, of polyglycerol and/or at least onehumectant selected from the group consisting of sorbitol, glycerine,polyethylene glycol, and macrogol glycerol fatty acid ester, or amixture thereof. In a preferred embodiment, component (c) may comprisean oleoyl macrogolglyceride or a mixture of oleoyl macrogolglycerides.

In a preferred embodiment, component (c) may comprise 1 to 20% byweight, preferably 1 to 10% by weight, more preferably 1 to 5% byweight, and most preferably at around 4% by weight of the formulation.

In another embodiment, the viscosity-regulating agent may comprise athickener or gelling agent selected from the group consisting ofcellulose and cellulose derivatives, polysaccharides, carbomers,polyvinyl alcohol, povidone, colloidal silicon dioxide, cetyl alcohols,stearic acid, beeswax, petrolatum, triglycerides and lanolin, or amixture thereof. More preferably, the viscosity-regulating agent iscolloidal silicon dioxide.

In a preferred embodiment, the viscosity-regulating agent may comprise0.5 to 10% by weight, preferably 0.5 to 5% by weight, more preferably 2to 5% by weight, and most preferably at around 4% by weight of theformulation.

While not wishing to be bound by theory, it is believed that nasaladministration of the galenical gel formulation of the presently claimedinvention may be able to facilitate selective recruitment of moleculesto brain tissue by providing access directly to the brain, which in turnmay provide for new clinical applications, for example, the use ofneurotransmitters to treat CNS disorders.

Accordingly, it is an object of the invention to not encompass withinthe invention any previously known product, process of making theproduct, or method of using the product such that Applicant reserves theright and hereby disclose a disclaimer of any previously known product,process, or method. It is further noted that the invention does notintend to encompass within the scope of the invention any product,process, or making of the product or method of using the product, whichdoes not meet the written description and enablement requirements of theUSPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of theEPC), such that Applicant reserves the right and hereby disclose adisclaimer of any previously described product, process of making theproduct, or method of using the product.

It is noted that in this disclosure and particularly in the claimsand/or paragraphs, terms such as “comprises”, “comprised”, “comprising”and the like can have the meaning attributed to it in U.S. patent law;e.g., they can mean “includes”, “included”, “including”, and the like;and that terms such as “consisting essentially of” and “consistsessentially of” have the meaning ascribed to them in U.S. patent law,e.g., they allow for elements not explicitly recited, but excludeelements that are found in the prior art or that affect a basic or novelcharacteristic of the invention.

These and other embodiments are disclosed or are obvious from andencompassed by, the following Detailed Description.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawings, in which:

FIG. 1 shows the effect of nasal dopamine gel on immobility and climbingof depressed rats.

FIG. 2 shows the concentration of dopamine and metabolites in nucleusaccumbens and neostriatum after nasal administration of dopamine.

DETAILED DESCRIPTION

The galenical gel formulation of the presently claimed invention ischemically and physically stable and can be in the form of a suspensionor a solution of the pharmacologically active substance. In a preferredembodiment, the galenical gel formulation of the invention is filledinto a preservative-free device able to accurately deliver doses of theabove formulation, even at a high viscosity.

After nasal application of the galenical gel formulation, the activeingredient or active ingredient particles are typically efficientlytrapped at the deposition site and are typically absorbed at apredictable rate across the mucous membrane of the patient, therebylimiting possible deactivation by metabolizing enzymes and/orprotein-binding.

It is also understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.

The term “higher availability” or “higher bioavailability” shall meanthat after application of the active ingredient(s), significant andconstant in vivo therapeutic drug concentrations, especially in thebrain, are maintained for an extended period of time.

The composition of the invention may comprise a neurotransmitter and/orneuromodulator agent. A neurotransmitter, as used herein, may be amolecule used for signaling between nerve cells or neurons.Neurotransmitter molecules typically pass between neurons at synapses,and may causes a rapid, short-lived and dramatic response.Neurotransmitters may degrade rapidly, resulting in restoration of theresting membrane potential. Examples include but are not limited toAcetylcholine, Monoamines (epinephrine, norepinephrine, dopamine,serotonin, melatonin, histamine), Amino acids (glutamate, gammaaminobutyric acid (GABA), aspartate, glycine), Purines (Adenosine, ATP,GTP, and their derivatives), neuroactive peptides (Substance P.N-Acetylaspartylglutamate), Neurohypophyseal transmitters (Oxytocin,Vasopressin), Opioids (Endorphin), zinc, nitric oxide, carbon monoxide,and chemical modifications of such molecules, such as esters.

Neurotransmitters such as dopamine, serotonin, epinephrine andnorepinephrine contain the catechol moiety typically synthesized fromthe amino acid tyrosine.

One neurotransmitter commonly associated with any number of responses isdopamine or 4-(2-aminoethyl)-1,2-benzenediol. Dopamine is commonlyregarded as an endogenous catecholamine with α and β adrenergicactivity.

L-DOPA is commonly synthesized from aminotyramine and converted intodopamine in the brain. Other neurotransmitters are typically containedin synaptic vesicles in terminals of the presynaptic neuron, and uponstimulation of an action potential, are released into the synaptic cleftto induce a response in the post synaptic cell. Iontophoresis of theneurotransmitter into a synaptic cleft induces the same postsynapticresponse. The neurotransmitter then degrades rapidly resulting inrestoration of the resting potential.

Other catecholamines known to have various utilities includeepinephrine, norepinephrine, and serotonin.

A neuromodulator agent, as used herein, may be a substance other than aneurotransmitter, released by a neuron at a synapse and conveyinginformation to adjacent or distant neurons, either enhancing ordampening their activities. Neuromodulation is the process in whichseveral classes of neurotransmitters in the nervous system regulatediverse populations of neurons. Neuromodulators may act not only on theinput system but may change the transformation itself to produce theproper contractions of muscles as output. Neuromodulator agents may alsoinclude neurosteroids. A variety of steroids are synthesized in thecentral and peripheral nervous system, especially in myelinating glialcells, from cholesterol or steroidal precursors imported from peripheralsources. Such steroids are defined as neurosteroids. Neurosteroids mayrapidly alter neuronal excitability through interaction withneurotransmitter-gated ion channels. In addition, neurosteroids may alsoexert effects on gene expression via intracellular steroid hormonereceptors. Examples include but are not limited to pregnenolone,dehydroepiandrosterone, their sulfates, and reduced metabolites such asthe tetrahydroderivative of progesterone 3α-hydroxy-5α-pregnane-20-one.Neuromodulator agents also include chemical modifications ofneurosteroids, such as esters and synthetic neurosteroids such asminaxolone, ganaxolone.

In a preferred embodiment, the active ingredient may comprise 0.01 to 6%by weight, preferably 0.1 to 4% by weight, more preferably 0.5 to 2% byweight, and most preferably at around 2% by weight of the formulation.

The carrier of the invention functions to dissolve or suspend the drugand otherwise support the various constituents of the invention. To thatend, the carrier has a lipophilic nature or character. Suitable familiesof oils include fatty acids and oils such as mineral and vegetable oils,in particular, fatty acids and oils derived from vegetable stock areespecially useful. Both linear and branched chain acids and oils areuseful including those oils and acids with various levels of saturationand substitution. Chain size including but is not limited to formic,acetic, propionic, butyric, valeric, caproic, emanthic, caprylic,pelargonic, capric, laurie, myristic, palmitic and stearic, amongothers, all represent useful oil and acid moieties.

The term “lipophilic carrier” may comprise, but is not limited to, fatsand/or vegetable oil such as castor oil, soybean oil, sesame oil, orpeanut oil, fatty acid esters such as ethyl- and oleyloleat,isopropylmyristate, medium chain triglycerides, glycerol esters of fattyacids, or polyethylene glycol, phospholipids, white soft paraffin, orhydrogenated castor oil, or a mixture thereof. In one embodiment, theactive ingredient may also be incorporated into an oil mixture. In apreferred embodiment, the vegetable oil is castor oil.

The particular amount of lipophilic carrier that constitutes aneffective amount is dependent on the particular viscosity regulatingagent used in the formulation. It is therefore not practical toenumerate specific amounts for use with specific formulations of theinvention.

In a preferred embodiment, the lipophilic carrier may comprise between30% and 98% by weight, preferably between 60 and 98% by weight, morepreferably between 75% and 95% by weight, even more preferably between85% and 95% by weight, and most preferably around 90% by weight of theformulation.

The surface active agent or surfactant of the invention functions todecrease surface tension in the composition of the invention.Surfactants are generally regarded as those compositions which have bothhydrophilic and lypophilic character. The lypophilic character of thesurfactant typically takes the form of a pendent moiety having little ifany charge. In turn, the hydrophilic character of the surfactant istypically charged and dictates the class into which the surfactant isidentified. For example, surfactants typically used in the inventioninclude nonionic surfactants, anionic surfactants, amphotericsurfactants, and cationic surfactants.

In one embodiment, component (c), a compound or a mixture of compoundshaving surface tension decreasing activity, may comprise at least asurfactant including, but not limited to, lecithin, fatty acid ester ofpolyvalent alcohols, fatty acid ester of sorbitanes, fatty acid ester ofpolyoxyethylensorbitans, fatty acid ester of polyoxyethylene, fatty acidester of sucrose, fatty acid ester of polyglycerol, and/or at least onehumectant such as sorbitol, glycerine, polyethylene glycol, or macrogolglycerol fatty acid ester. Particularly useful, however, are oleoylmacrogolglycerides (such as LABRAFIL® 1944 CS, as available fromGattefosse (Saint-Priest, France)).

As defined herein, “surface tension decreasing activity” shall meanhaving a surface tension that results in generating contact of theformulation to the hydrophilic mucous membranes of the nasal cavity.

In one embodiment, the active ingredient/neurotransmitter may beincorporated into a surfactant mixture. The particular amount ofsurfactant that constitutes an effective amount is dependent on theparticular oil or oil mixture used in the formulation. It is thereforenot practical to enumerate specific amounts for use with specificformulations of the invention. Typically, however, the surfactant maycomprise 1 to 20% by weight, preferably 1 to 10% by weight, morepreferably 1 to 5% by weight, and most preferably at around 4% by weightof the formulation.

The term “viscosity-regulating agent” shall mean a thickener or gellingagent.

Examples of a viscosity-regulating agent include, but are not limitedto, cellulose and derivatives thereof, polysaccharides, carbomers,polyvinyl alcohol, povidone, colloidal silicon dioxide, cetyl alcohols,stearic acid, beeswax, petrolatum, triglycerides, lanolin, or the like.A preferred viscosity regulating agent is colloidal silicon dioxide(such as AEROSILO®, as available from Degussa).

The incorporation of the active ingredient is also possible into amixture of thickeners or gelling agents. The particular amount ofthickener/gelling agent that constitutes an effective amount isdependent on the particular oil or oil mixture used in the formulation.It is therefore not practical to enumerate specific amounts for use withspecific formulations of the invention. Typically, however, thethickener/gelling agent(s) may comprise 0.5 to 10% by weight, preferably0.5 to 5% by weight, more preferably 2 to 5% by weight, and mostpreferably at around 4% by weight of the formulation.

Preferred weight percentages for components of the galenical gelformulation are shown in Table 1.

TABLE 1 Preferred weight percentages components of the galenical gelformulation Wt-% Useful Preferred More Preferred Active Ingredient 0.01to 6   2 to 4 0.5 to 2   (e.g. Neurotransmitter/ Neuromodulator agentLipophilic Carrier 30 to 98 60 to 98 85 to 95 Surfactant  1 to 20  1 to10 1 to 5 Viscosity Regulating 0.5 to 10  0.5 to 5   2 to 5 Agent

Generally, the galenical formulation of the invention can be preparedeasily by the following conventional method:

The lipophilic carrier and surfactant are filled into a stirrer vesseland about 75% of the viscosity regulating agent is mixed in. The activeingredient is added while stirring to obtain a homogenous dispersion ofthe active ingredient. Next, the formulation is adjusted to thenecessary viscosity with the remainder of the viscosity regulatingagent.

In a preferred embodiment, the formulation may be filled into apreservative-free container.

Because the active ingredient, particularly a neurotransmitter, may havelower levels of solubility in water, release from the formulation is therate-limiting step for adsorption. The presently claimed inventiondemonstrates that the incorporation of the active ingredient into anoily formulation containing a suitable surfactant leads tophysiologically clinically effective serum and brain levels and to anappropriate sustained action of the active ingredient over time.

This sustained and clinically favorable release of the active ingredientis due to the interaction of the compounds in the oily carrier, whichremains on the mucous membrane of the nasal cavity for a prolongedduration of time.

The active ingredient of this invention may be introduced into theformulation also in a processed form, such as microspheres, liposomes,among others.

The formulation according to this invention may also be processed intopowder form, such as by lyophilization or spray-drying.

The most preferred formulation of the presently claimed invention ispresented in Table 2.

TABLE 2 Most Preferred formulation Compound Amount per containerDelivery per spray Dopamine/L-DOPA 2% ~2.8 mg Colloidal silicon dioxide4% ~4.2 mg Oleoyl macrogol-glycerides 4% ~5.6 mg Castor Oil 90% ~127.4mg 

In one embodiment, the formulation is administered to a patient. In apreferred embodiment, the formulation is administered to a human.

When administered to a patient, the formulation that optionallycomprises a pharmaceutically acceptable vehicle may be administered byabsorption through mucocutaneous linings and may be administeredtogether with another biologically active agent. Administration may belocal.

In a specific embodiment, the term “pharmaceutically acceptable” meansapproved by a regulatory agency of the Federal or a state government orlisted in the U.S. Pharmacopeia or other generally recognizedpharmacopeia or otherwise proven as safe for use in animals, mammals,and more particularly in humans. The term “vehicle” refers to a diluent,adjuvant, excipient, or carrier with which a compound of the inventionis administered. Such pharmaceutical vehicles can be lipophilicsemisolids or liquids such as oils, including those of petroleum,animal, vegetable or synthetic origin, such as peanut oil, soybean oil,mineral oil, sesame oil and the like.

The amount of the formulation that will be effective in the treatment ofa particular disease will depend on the nature of the disease, and canbe determined by standard clinical techniques. In addition, in vitro orin vivo assays may optionally be employed to help identify optimaldosage ranges. The precise dose to be employed will also depend on theseriousness of the disease, and should be decided according to thejudgment of the practitioner and each patient's circumstances.

Recommended dosages for administration by inhalation are in the range ofabout 0.001 milligram to about 200 milligrams per kilogram of bodyweight per day. Effective doses may be extrapolated from dose-responsecurves derived from in vitro or animal model test systems. Such animalmodels and systems are well known in the art.

The formulation is preferably assayed in vitro and in vivo, for thedesired therapeutic or prophylactic activity, prior to use in humans.Animal model systems can be used to demonstrate safety and efficacy.

EXAMPLES

The invention will now be further described by way of the followingnon-limiting examples.

Example 1 Nasal Administration of Dopamine to Rats

A dopamine (DA) gel of the inventive formulation was nasallyadministered to rats used in the validated “forced swimming test.” Asshown in FIG. 1, the administration of dopamine results inanti-depressive-like effects. As shown in FIG. 2, strong dopaminergicactivity in the neostriatum and ventral striatum (nucleus accumbens) wasobserved after nasal application of dopamine with the inventiveformulation.

Generally, antidepressants must be administered for an extended lengthof time before antidepressive effects are observed. Surprisingly, afternasal application to rat of the dopamine gel formulation, antidepressiveeffects occurred within hours and without any observable side effects,such as those side effects known to occur with desipramine (apathy) orfluoxetine (weight loss).

After nasal application to rats of dopamine in the inventive gelformulation, the concentration of dopamine in the nucleus accumbens andneostriatum level increased rapidly by more than 1000 percent. Theseresults differ from those previously described. After nasal applicationof an aqueous dopamine solution to mice, Bjorn Jansson, ComprehensiveSummaries of Uppsala Dissertations from the Faculty of Pharmacy 305(2004), found dopamine in the olfactory bulb but the compound peakedafter four hours. After nasal application to rats of aqueous dopaminesolution, Maria Dahlin, Comprehensive Summaries of Uppsala Dissertationsfrom the Faculty of Pharmacy 240 (2000), found dopamine in CSF after ashort time but the increase of the compound from baseline was much lowerthan with the nasal gel of the invention. Ikeda et al., Chem. Pharm.Bull. 40(8): 2155-2158 (1992), increased bioavailability ofnasally-given dopamine by some degree using the excipients hydroxypropylcellulose (HPC) and Azone (l-dodecylazacycloheptan-2-one), respectively.De Souza Silva et al., Synapse 27:294-302 (1997), showed that by nasallyapplying to rats an aqueous L-DOPA methyl ester solution (50 mg/kg), thedopamine level in the neostriatum were increased by about 130%. Themetabolites 3,4-dihydroxyphenyl acetic acid (DOPAC) and homovanillicacid (HVA) slightly increased by contrast to what was seen afterintraperitoneal (IP) application of L-DOPA methyl ester in De SouzaSilva et al., J. Neurochem. 68(1): 233-239 (1997).

Furthermore, the metabolism of dopamine appears to be quite differentthan that previously described. Unexpectedly, as shown in FIG. 2,dopamine in the CSF was not metabolized to 3,4-dihydroxyphenyl aceticacid (DOPAC) or homovanillic acid (HVA) as is typically seen. Theseresults demonstrate that nasal application of dopamine in the inventivegel formulation may be useful for the treatment of diseases associatedwith dopamine deficiency in the brain, such as Parkinson's disease,attention deficit hyperactivity disorder (ADHD), and addiction to drugsand/or alcohol.

The features disclosed in the foregoing description, in the claimsand/or in the drawings may, both separately and in any combinationthereof, be material for realizing the invention in diverse formsthereof.

Having thus described in detail preferred embodiments of the presentinvention, it is to be understood that the invention defined by theabove paragraphs is not to be limited to particular details set forth inthe above description as many apparent variations thereof are possiblewithout departing from the spirit or scope of the present invention.

1.-26. (canceled)
 27. A dopamine gel formulation for nasaladministration comprising: (a) dopamine; (b) at least one lipophilic orpartly lipophilic carrier; (c) a compound or a mixture of compoundshaving surface tension decreasing activity; and (d) aviscosity-regulating agent.
 28. The dopamine gel formulation accordingto claim 27, wherein said dopamine is present in an amount of from about0.01% to about 6% by weight of the dopamine gel formulation.
 29. Thedopamine gel formulation according to claim 27, wherein said at leastone lipophilic or partly lipophilic carrier is present in the dopaminegel formulation in an amount of from about 30% to about 98% by weight ofthe dopamine gel formulation.
 30. The dopamine gel formulation accordingto claim 27, wherein said at least one lipophilic carrier or partlylipophilic carrier is selected from a group consisting of a fat, oil,wax, cholesterol, sterol, monoglyceride, diglyceride, triglyceride,phospholipid and mixtures thereof.
 31. The dopamine gel formulationaccording to claim 30, wherein said oil is castor oil.
 32. The dopaminegel formulation according to claim 27, wherein said compound or mixtureof compounds having surface tension decreasing activity is present in anamount of from about 1% to about 20% by weight of the dopamine gelformulation.
 33. The dopamine gel formulation according to claim 27,wherein said compound or mixture of compounds having surface tensiondecreasing activity comprises at least one surfactant selected from thegroup consisting of lecithin, a fatty acid ester, at least onehumectant, and mixtures thereof.
 34. The dopamine gel formulationaccording to claim 33, wherein said compound or mixture of compoundshaving surface tension decreasing activity comprises an oleoylmacrogolglyceride or mixtures of oleoyl macrogolglycerides.
 35. Thedopamine gel formulation according to claim 27, wherein saidviscosity-regulating agent is present in an amount of from about 0.5% toabout 10% by weight of the dopamine gel formulation.
 36. The dopaminegel formulation according to claim 27, wherein said viscosity-regulatingagent comprises a thickener or gelling agent selected from the groupconsisting of cellulose, cellulose derivatives, polysaccharides,carbomers, polyvinyl alcohol, povidone, colloidal silicon dioxide, cetylalcohols, stearic acid, beeswax, petrolatum, triglycerides, lanolin andmixtures thereof.
 37. The dopamine gel formulation according to claim36, wherein said viscosity-regulating agent is colloidal silicondioxide.
 38. The dopamine gel formulation according to claim 27, whereinsaid dopamine is in the form of microspheres.
 39. The dopamine gelformulation according to claim 27, wherein said dopamine is in the formof liposomes.
 40. A dopamine gel formulation comprising: (a) dopamine inan amount of from about 0.01% to about 6% by weight of the formulation;(b) at least one lipophilic or partly lipophilic carrier in an amount offrom about 30% to about 98% by weight of the formulation; (c) a compoundor a mixture of compounds having surface tension decreasing activitypresent in an amount of from about 1% to about 20% by weight of theformulation; and (d) a viscosity-regulating agent present in an amountof from about 0.5% to about 10% by weight of the formulation.
 41. Adopamine gel formulation comprising: (a) dopamine in an amount of about2% by weight of the formulation; (b) castor oil in an amount of about90% by weight of the formulation; (c) an oleoyl macrogolglyceride or amixture of oleoyl macrogolglycerides in an amount of about 4% by weightof the formulation; and (d) colloidal silicon dioxide in an amount ofabout 4% by weight of the formulation.